Imipramine-flupenthixol decanoate interaction

Augmentation with antidepressants in schizophrenia treatment: benefit or risk

We focused on the application of antidepressants in schizophrenia treatment in this review. Augmentation of antidepressants with antipsychotics is a common clinical practice to treat resistant symptoms in schizophrenia, including depressive symptoms, negative symptoms, comorbid obsessive-compulsive symptoms, and other psychotic manifestations. However, recent systematic review of the clinical effects of antidepressants is lacking. In this review, we have selected and summarized current literature on the use of antidepressants in patients with schizophrenia; the patterns of use and effectiveness, as well as risks and drug-drug interactions of this clinical practice are discussed in detail, with particular emphasis on the treatment of depressive symptoms in schizophrenia.

Clinical pharmacokinetics of drugs used to treat urge incontinence

Urge incontinence (also known as overactive bladder) is a common form of urinary incontinence, occurring alone or as a component of mixed urinary incontinence, frequently together with stress incontinence. Because of the pathophysiology of urge incontinence, anticholinergic/antispasmodic agents form the cornerstone of therapy. Unfortunately, the pharmacological activity of these agents is not limited to the urinary tract, leading to systemic adverse effects that often promote nonadherence. Although the pharmacokinetics of flavoxate, propantheline, scopolamine, imipramine/desipramine, trospium chloride and propiverine are also reviewed here, only for oxybutynin and tolterodine are there adequate efficacy/tolerability data to support their use in urge incontinence. Oxybutynin is poorly absorbed orally (2-11% for the immediate-release tablet formulation). Controlled-release oral formulations significantly prolong the time to peak plasma concentration and reduce the degree of fluctuation around the average concentration. Significant absorption occurs after intravesical (bladder) and transdermal administration, although concentrations of the active N-desethyl metabolite are lower after transdermal compared with oral administration, possibly improving tolerability. Food has been found to significantly affect the absorption of one of the controlled-release formulations of oxybutynin, enhancing the rate of drug release. Oxybutynin is extensively metabolised, principally via N-demethylation mediated by the cytochrome P450 (CYP) 3A isozyme. The pharmacokinetics of tolterodine are dependent in large part on the pharmacogenomics of the CYP2D6 and 3A4 isozymes. In an unselected population, oral bioavailability of tolterodine ranges from 10% to 74% (mean 33%) whereas in CYP2D6 extensive metabolisers and poor metabolisers mean bioavailabilities are 26% and 91%, respectively. Tolterodine is metabolised via CYP2D6 to the active metabolite 5-hydroxymethyl-tolterodine and via CYP3A to N-dealkylated metabolites. Urinary excretion of parent compound plays a minor role in drug disposition. Drug effect is based upon the unbound concentration of the so-called 'active moiety' (sum of tolterodine + 5-hydroxymethyl-tolterodine). Terminal disposition half-lives of tolterodine and 5-hydroxymethyl-tolterodine (in CYP2D6 extensive metabolisers) are 2-3 and 3-4 hours, respectively. Coadministration of antacid essentially converts the extended-release formulation into an immediate-release formulation. Knowledge of the pharmacokinetics of these agents may improve the treatment of urge incontinence by allowing the identification of individuals at high risk for toxicity with 'usual' dosages. In addition, the use of alternative formulations (controlled-release oral, transdermal) may also facilitate adherence, not only by reducing the frequency of drug administration but also by enhancing tolerability by altering the proportions of parent compound and active metabolite in the blood.

Depression in schizophrenia: recognition and management in the USA

The recognition of depression as a distinct syndrome within schizophrenia is a relatively recent development. The International Survey of Depression in Schizophrenia was designed to evaluate current clinical practice and prescribing trends in the management of the depressive component of schizophrenia. A 48-item questionnaire, comprising fixed-response questions and questions stimulated by case scenarios, was distributed to 37513 psychiatrists in the USA. A total of 43484 psychiatrists in Canada, Australia and 21 European countries also received the questionnaire. A total of 1128 US psychiatrists responded. Analysis of the data revealed that US psychiatrists identify symptoms of depression in approximately one-third of patients with schizophrenia, and largely appreciate the magnitude of the resultant burden on patients and their families. Responses to questions regarding treatment approaches and case scenarios demonstrated that the level of adjunctive prescribing of antidepressants in the USA is often higher than in other regions. Levels of awareness of depression in patients with schizophrenia and recognition of the need for effective management appear to be high among US psychiatrists. However, more than a quarter of these specialists rarely or never prescribe adjunctive antidepressant medications. Disparities in treatment approaches varying from the existing scientific evidence base underscore the need for further investigation into ways of optimizing the management of this serious coexisting condition.